Published 4:00 am, Monday, June 25, 2007

Drug resistant breeds of staph bacteria are far more prevalent among hospitalized patients in the United States than previously thought, according to a new survey by an organization of nurses and technicians who specialize in infection control.

The study, released Sunday evening in advance of a San Jose health care convention, screened patients in hospitals and long-term care homes to detect MRSA, or methicillin-resistant Staphylococcus aureus, which is not only resistant to common antibiotics, but kills patients at 2 1/2 times the rate of more drug-susceptible staph germs.

In a survey of 1,237 hospitals and other residential health care centers such as nursing homes, researchers found that 3.4 percent of patients were infected with MRSA -- a rate 8.6 times greater than estimated by the Centers for Disease Control and Prevention. CDC epidemiologists estimated the rate at 0.4 percent in 2005.

Unseen until the late 1970s, MRSA now accounts for between 50 and 70 percent of all staph infections acquired in U.S. hospitals, and new strains of the bug have taken hold outside the health care setting, afflicting otherwise healthy individuals with "spider bite" boils that are difficult to treat, often recur, and can become life-threatening blood infections.

The latest study was conducted by the Association for Professionals in Infection Control & Epidemiology, or APIC, an organization whose 11,000 members include nurses charged with keeping infections out of the health care setting.

It is estimated that each year 2 million Americans become infected during hospital stays, and at least 90,000 of them die. MRSA is a leading cause of hospital-borne infections.

"This study is a real wake-up call to health care workers," said Kathy Warye, chief executive of APIC. "It presents a much more comprehensive picture of the burden of MRSA."

The survey was conducted in the fall of 2006, and represents a "snapshot" of MRSA rates during a single day in the participating institutions. The hospitals and nursing homes toted up the number of confirmed MRSA infections in their patient population on one day -- selected by each institution -- during the study period.

One of the more surprising findings was that 67 percent of MRSA cases were associated with patients who were hospitalized for non-surgical medical conditions. Most infection control efforts focus on the intensive care units, where patients with trauma or surgical wounds are deemed particularly vulnerable.

Warye said the study should prompt individual hospitals to conduct their own studies of where the MRSA risk exists. Other infection control efforts include isolation of infected patients, the use of barriers such as gloves, caps and gowns, and thorough cleaning of the facilities. "Hand hygiene is a critical component," she said. "It is still, first and foremost, the most important way to reduce risk of transmission."

Unlike other MRSA surveys, this one also tallied cases of drug-resistant staph colonization among patients. About 1 in 3 institutions conducted what is known as active surveillance, swabbing the nostrils of newly admitted patients to see if they harbored MRSA. It is not uncommon for individuals to carry colonies of MRSA in the nose, vagina or rectum, but show no signs of illness. Infection control experts are concerned, however, that these same colonized patients might transmit their infections inadvertently to weaker patients in the hospital.

When the colonized patients were counted in addition to those infected, the MRSA rates in the participating institutions rose to 4.6 percent.

Lisa McGiffert, manager of Consumers Union's Stop Hospital Infections project, in Austin, Texas, said the survey results are strong evidence that the problem is severe and widespread. "These are dangerous infections, and there is not enough being done to protect patients from getting them," she said. "Hospitals are going to have to do more. They have to be more aggressive, and it's just not happening."

McGiffert has been advocating for state laws that would require hospitals to report their infection rates. Seventeen states have done so, but Gov. Arnold Schwarzenegger vetoed a bill in 2005 that would have added California to that list.

Accurate data on hospital-borne infections are hard to come by, in part because of industry objections to reporting their rates. The Centers for Disease Control and Prevention makes estimates based primarily on discharge data from about 300 representative hospitals that share the information confidentially with the federal agency.

Dr. William Jarvis, a former CDC scientist who consulted with APIC on the survey, said that the federal data are based primarily on reports from teaching hospitals, while the new study -- with much broader institutional participation -- shows that the MRSA problem extends well beyond the nation's largest medical centers.

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